Process of desulphurizing motor fuels and improving octane rating



has... Mar. 20, 1945 zsiaou PROCESS OF DESULPHURIZING MOTOR FUELS AND IMPROVING OCTANE RAT- Minor C. K. Jones, Mountainside, N. 1., anlgnor to Standard Oil Development Company, a corporation of Delaware No Drawing. Application October 24, 1942;

Serial No. 483,220 r Claims. (01. 198-23) The present invention relates to improvements in the art of treating sour hydrocarborroils and, more particularly, it relates to improvements in a catalytic process for converting sour hydrocarbon oil into a sweetened product.

Prior to my invention, numerous methods had been proposed for sweetening sour gasoline and other hydrocarbon oils. A commonly used method was the treatment of a sour hydrocarbon oil with the lead doctor solution which is a solution of sodium plumbite in water. This treatment with the sodium plumbite is normally followed with the addition of sulphur followed by settling to yield a product substantially free of the oifensive odor of mercaptans and other foul smelling constituents of the sour oil. The theory of the lead solution treatment is that the mercaptans present in the sour oil are oxidized to the corresponding disulphides which latter components are substantially non-odoriferous, and although there is no net reduction in sulphur content of the treated oil, nevertheless the form in which the sulphur is present is substantially less offensive than the form in which it is present in the sour 011. There are also methods of sweetening sour hydrocarbon oils by treating the sour oil usually in the presence of cupric chloride supported on clay with oxygen or oxygen-containing gas. Here also the theory of the operation is that the cupric chloride oxidizes the foul smelling mercaptans to disulphides and is itself reduced to cuprous chloride. The thu reduced copper salt is oxidized from its cuprous form to the cupric form in situ for further use. Various other methods have been proposed for sweetening sour hydrocarbon oils.

My invention, on the other hand, involves a catalytic desulphurization where the total sulphur content of the sour oil is appreciably reduced and mercaptan sulphur is removed to yield a sweet product without additional treatment, the

- ume of catalyst per hour while maintaining a pressure of about atmospheric on the system. One catalyst which I employed had the following composition:

Percent by weight Clay 55 Stoneware grog 20 Cuprous oxide 20 Chromium sesquioxide 5 Percent Clay 37.5 Magnesite 37.5 Cuprous oxide 20.0 Chromium sesquioxi'de 5.0

Under the above conditions, I made two runs. one at 900 F. and the other at 950 F., and I have set forth these results in the following tabu lation: I found that the total sulphur was reduced about 20%.

Desulphurization of Venezuelan cracked naphtha containing 0.35% by weiaht sulphur with Caro-437203 catalyst Feed m Run 1 Run 2 Operatin conditions:

Catafyst Pliled CUrO'CUOi on clay 900 950 Atmos. Atmos. 1. 0 l. 0 6 8 Jatalyst regeneretions None 1 Ci'gi'ecteti1 ields wt.+l00% lrecy e: Dry .-..weight per cent 0.72 1. 18 Case ine-- volume per cent.. 100 90. 0 94. 8 Polymer do 3. 0 3. 0 Coke ..weight per oent 0. 27 0. 28 Actual gasoline inspections:

Bromine number ..cg/g 66.0 63. 4 54. I Doctor test DNP Pass Pass Cap rnumber 8 S p ur.. ..wei ht per cent 0.350 0 87 0.203 Sulphur remov ...per cent.. 18 i7 Fecal 1 mm; Run 3 2.1.11 2

Octane number:

AS Ivl-.:lmr. 67.1 as s in. e +8.0 Sui. TEL] 78.1 77. 5 is. D C FR*RJJ.CZBQY 72$. 0 7B. '3 L"). 9 +3.0 85.0 86.1 813.6 ()clonc imorovem nt Til-clear. 1. s :s. s 1.4 '13 2.2 2.9 1.1 2.5 Ll) 1.1 50.0 P10 1.0 23.5 29.6 (10.0 ($0.0 89.0 33.5 53.0 53% 391 93.5 98.5 Mas 0.6 0. 6 Running gas anslynio cfcciilc grevit (air-i) 0. ass 0. =55) l ydrogeu v0 urns par act 72. Z) 57. 7 Methso ..r.io 12.7 13.3 Ethane. 6.0". 4.5 7.5 Ethylen do.-. 4. s 7. 0 Propane .do.- 1.4 2.5 Propylene moo... 2.5 8.9 Butsnes "do-.. 0. ii i). 7 Butylcu do. 1.2 l. 7 Eeooverebls butane:

Weight per cent 0.0) 0.14 Volume per cent 0. ii 0.15

l Corrected to 0:, N; and 00 free basis.

After the cstalyst heel heen employee ior 6 hours, it became necessary to regenerate the out alyst to remove sulphur compounds capacitor. therein by contact with the oil. This regen -era tion was accomplished by passing air at temp-em tures between 808 and 1100 F. through the cct= aiyst whereupon the sulphur compounds were consumed by combustion. During this reccneretion operation, it is advisable to maintain a back pressure or about 2 atmospheres on the catalyst undergoing regeneration, since this added pres sure lowers'the ignition temperature or. the com taminants and the catalyst therefore may he safe 1y regenerated rapidly. As usual, in a catalyst containing clay the same should not be heated above 1100" F. since heating above this mmperm ture is apt to-cause impairment of the catalyst by baking and fusion.

A very important advantage of the present invention over other catalytic processes is that hy drogen sulphide is removed simultanetuiciy with mercaptans, and accordingly, in addition. to oh= accuses iainiuc a reduction of sulphur, a doctor ow 9,1111 hyrircgen sulphide product clots-ii rcculringnc subsequent tree itment to peas cioc specification or for hydro en sulphide rein Ari incidental feature of my invention 1'" the treatment results, in the case gasoi'hie rlssulphurizatiori, in a, distinct number improvemeut. For smpie, in the curl run which I mace and which is set shove, the treatment was carried out a perature of 959 1 and the improvement in 0-2 number was about 3.

To recapitulate, my present invention relates to improvements in the catalytic rlesuiphuri of sour hydrocarbon oils. E have found the. catalyst containing cloy, cuprous oxide and oxide of the V2 group oi the periodic system, :3 as chromium s-esquioxide, when contacted with o. sour hydrocarbon oil at high temperatures ro= moves considerable sulphur from the saisl oil and thcrehy awe-stems the same and, furthermore, thet the treatment results in distinct improvement in the octane number oi the treated heohtha or gasoline,

What 1 claim is:

i. Eu 9. process for simultaneously clesuiphuri-z log; a sour hydrocarbon oil anti raising its 0 rating, the improvement which comprises com. ing the oil in vapor phase at elevated temperature with a catalyst which when pieced in use contains :2. major proportion of cupi'ous oxide hurl minor proportion of on music of a metal of the VI- group of the periodic system, said oxides supported on a carrier.

2. F ethoci according to claim 1, in which a sour i'iuphthu is the iced stool; and it is contacted with the catalyst at a temperature within the range of about coo to 950 F. and a pressure of about atmospheric for an extended period of time.

3. Method according to claim 1, in which the oxide of the VI group metal is chromium cuioxicie.

l. Method according to claim 1, in which the catalyst contains approximately 29% ouprous orz= icie, 5% chromium sesuuioxicie and carrier.

5. Method according to claim 1, in which the catalyst contains. approximately 37.5% clay, 37.5% magnesite, 20% cuprous oxide, anti 5% chromium sesquioxide.

MINOR C. K. JONES. 

